1. Field of the Invention
The present invention relates to a method for manufacturing a master disk for magnetic transfer, in particular, a method for manufacturing a master disk for magnetic transfer which is preferable to transfer magnetic information such as format information to a magnetic disk used in a hard disk equipment and the like.
2. Description of the Related Art
Recently a magnetic disk (hard disk) used in a hard disk drive has spread rapidly, and has generally format information and address information written therein before installed in a drive after delivered to a drive manufacturer from a magnetic disk manufacturer. The writing can be executed by a magnetic head; however, it is more effective and preferable to transfer the writing in a batch from a master disk with format information and address information written therein.
In the magnetic transfer method for transferring information in a batch, a master disk and a disk to be transferred (slave disk) are in close contact with each other with a magnetic field producing device(s) such as an electromagnetic device or a permanent magnet device being provided on one surface or both surfaces of the disks to apply a magnetic field for transfer, so that information on the master disk (e.g., servo signals) is magnetically transferred to the slave disk. To achieve the magnetic transfer with high accuracy, it is critical to make a master disk and a slave disk be in close contact with each other evenly without any gap between them.
The master disk which is used for the magnetic transfer method is usually a substrate having a surface formed with an convexoconcave pattern which corresponds to information signals and the surface of the convexoconcave pattern being covered with a magnetic layer. The master disk for magnetic transfer is generally manufactured with a method including a step of laminating a metal disk which consists of an electroformed layer on an original on which an convexoconcave pattern of information is formed to electroform the original so that the convexoconcave pattern is transferred to a surface of the metal disk, a step of removing the metal disk from the original, a step of stamping the removed metal disk into a predetermined size, and a step of covering a surface of the transferred convexoconcave pattern with a magnetic layer (See Japanese Patent Application Laid-Open No. 2001-256644, for example).